# Alignment-free characterization of polarizing beamsplitters

## TL;DR

This paper introduces a novel alignment-free method for characterizing polarizing beamsplitters using unpolarized light and a Faraday Mirror, enabling quick and precise measurements without complex setup or alignment.

## Contribution

The method allows for accurate PBS parameter measurement with unpolarized light, eliminating the need for alignment and time-varying signals, simplifying the process significantly.

## Key findings

- Achieves precise extinction ratio and insertion loss measurements
- Requires only three single-sweep measurements
- Does not need alignment or polarized light sources

## Abstract

Traditional methods for measurement of Polarizing Beamsplitter (PBS) parameters, especially the extinction ratio, require highly polarized light sources, alignment procedures and/or experimental parameters that change over time, such as polarization rotations. In this work, a new method is presented, which employs unpolarized light and a Faraday Mirror. It is shown that precise extinction ratio and insertion loss values can be achieved in three single-sweep measurements, without any alignment requirements or time-varying signals of any kind.